1. Field of the Invention
This invention relates to instruments for the boring of bones to remove a cylindrical section of bone for medical purposes. For example, the purpose of the bone removal may be for a biopsy, the extraction of pins, screws or other foreign bodies, or as a preparatory step for other procedures such as in the harvesting of small amounts of bone-graft material.
2. Description of the Prior Art
There are a number of instruments of the indicated type currently available on the market, such as, for example, the CORB Counterrotating Biopsy Needle manufactured by Zimmer Manufacturing Company, the Bordier Trephine, the Zimmer Bone Biopsy needle manufactured by the Zimmer Manufacturing Company, and the Lane-Trent Biopsy Needle.
The present-day instruments on the market are available as either manual or power-operated devices. One of the main problems with the manual devices in use today is that they require the surgeon to "bore" his way through bone in a procedure which requires him to re-grip the instrument after each turn. This affects the quality of the "cut" and makes the procedures cumbersome for the surgeon. A major problem with the power-operated devices is that they often produce cores of bone which, on histologic inspection, are filled with bone dust and debris thereby obscurring detail. Another problem with prior art devices is that they are incapable of use throughout a range of metabolic bone diseases that include brittle as well as sclerotic (hard) bone.